全文获取类型
收费全文 | 30962篇 |
免费 | 295篇 |
国内免费 | 265篇 |
专业分类
安全科学 | 805篇 |
废物处理 | 1278篇 |
环保管理 | 4065篇 |
综合类 | 5568篇 |
基础理论 | 7742篇 |
环境理论 | 10篇 |
污染及防治 | 8243篇 |
评价与监测 | 1963篇 |
社会与环境 | 1687篇 |
灾害及防治 | 161篇 |
出版年
2022年 | 216篇 |
2021年 | 242篇 |
2019年 | 228篇 |
2018年 | 400篇 |
2017年 | 403篇 |
2016年 | 654篇 |
2015年 | 528篇 |
2014年 | 788篇 |
2013年 | 2385篇 |
2012年 | 917篇 |
2011年 | 1257篇 |
2010年 | 985篇 |
2009年 | 1160篇 |
2008年 | 1303篇 |
2007年 | 1397篇 |
2006年 | 1239篇 |
2005年 | 1020篇 |
2004年 | 1061篇 |
2003年 | 1022篇 |
2002年 | 983篇 |
2001年 | 1229篇 |
2000年 | 847篇 |
1999年 | 544篇 |
1998年 | 390篇 |
1997年 | 390篇 |
1996年 | 442篇 |
1995年 | 450篇 |
1994年 | 443篇 |
1993年 | 406篇 |
1992年 | 368篇 |
1991年 | 360篇 |
1990年 | 366篇 |
1989年 | 327篇 |
1988年 | 325篇 |
1987年 | 299篇 |
1986年 | 274篇 |
1985年 | 279篇 |
1984年 | 318篇 |
1983年 | 315篇 |
1982年 | 308篇 |
1981年 | 294篇 |
1980年 | 256篇 |
1979年 | 266篇 |
1978年 | 223篇 |
1977年 | 199篇 |
1976年 | 179篇 |
1975年 | 185篇 |
1974年 | 175篇 |
1973年 | 174篇 |
1972年 | 174篇 |
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
921.
de Moura Stéfany G. Dauzakier Ligiane C. L. Pereira Leydiane O. Ramalho Teodorico C. de Oliveira Luiz C. A. Magalhães Fabiano 《Environmental science and pollution research international》2021,28(31):42093-42106
Environmental Science and Pollution Research - Water contamination is a common problem, especially considering dyes and drugs disposal. A possible and effective treatment method to remove these... 相似文献
922.
Vicente Estela Domingos Alves Célia A. Martins Vânia Almeida Susana Marta Lazaridis Mihalis 《Environmental science and pollution research international》2021,28(46):65385-65398
Environmental Science and Pollution Research - Residential settings are of utmost importance for human exposure, as it is where people spend most of their time. Residential wood combustion is a... 相似文献
923.
A simple approach to enhance the photocatalytic activity of red phosphorus(P) was developed.A mechanical ball milling method was applied to reduce the size of red P and to deposit graphene quantum dots onto red P. The product was characterized by scanning electron microscopy, transmission electron microscopy, contact angle measurements, zeta-potential measurements, X-ray diffraction and UV–vis absorption spectroscopy. The product exhibited high visible-light-driven photocatalytic performance in the photodegradation of rhodamine B. 相似文献
924.
This short paper presents an investigation on how human activities may or may not affect precipitation based on numerical simulations of precipitation in a benchmark case with modified lower boundary conditions, representing different stages of urban development in the model. The results indicate that certain degrees of urbanization affect the likelihood of heavy precipitation significantly, while less urbanized or smaller cities are much less prone to these effects. Such a result can be explained based on our previous work where the sensitivity of precipitation statistics to surface anthropogenic heat sources lies in the generation of buoyancy and turbulence in the planetary boundary layer and dissipation through triggering of convection. Thus only mega cities of sufficient size, and hence human-activity-related anthropogenic heat emission, can expect to experience such effects. In other words, as cities grow, their effects upon precipitation appear to grow as well. 相似文献
925.
Jagmohan Sharma Sujata Upgupta Rajesh Kumar Rajiv Kumar Chaturvedi G. Bala N H Ravindranath 《Mitigation and Adaptation Strategies for Global Change》2017,22(1):29-44
Assessment of vulnerability is an important step in building long-term resilience in the forestry sector. The objective of this paper is to present a methodological approach to assess inherent vulnerability of forests at landscape level. The approach involves use of vulnerability indicators, the pairwise comparison method, and geographic information system (GIS) tools. We apply this approach to assess the inherent vulnerability of forests of the Western Ghats Karnataka (WGK) landscape, which is a part of the Western Ghats biodiversity hotspot in India. Four vulnerability indicators, namely biological richness, disturbance index, canopy cover, and slope, are selected. We find that forests in 30, 36, 19, and 15 % grid points in this region show low, medium, high, and very high inherent vulnerability, respectively. The forest showing high and very high inherent vulnerability are mostly dry deciduous forests and plantations located largely on the eastern side of the landscape. We also find that canopy cover is one of the key indicators that determine the inherent vulnerability of forests, and natural forests are inherently less vulnerable than man-made plantations. Spatial assessment of inherent vulnerability of forests at landscape level is particularly useful for developing strategies to build resilience to current stressors and climate change in future. 相似文献
926.
Simone Guadagnucci Morillo Adriana Luchs Audrey Cilli Cibele Daniel Ribeiro Rita de Cássia Compagnoli Carmona Maria do Carmo Sampaio Tavares Timenetsky 《Food and environmental virology》2017,9(2):142-148
Norovirus (NoV) is recognized as the most common cause of foodborne outbreaks. In 2014, an outbreak of acute gastroenteritis occurred on a cruise ship in Brazil, and NoV became the suspected etiology. Here we present the molecular identification of the NoV strains and the use of sequence analysis to determine modes of virus transmission. Food (cream cheese, tuna salad, grilled fish, orange mousse, and vegetables soup) and clinical samples were analyzed by ELISA, conventional RT-PCR, qRT-PCR, and sequencing. Genogroup GII NoV was identified by ELISA and conventional RT-PCR in fecal samples from 5 of 12 patients tested (41.7%), and in the orange mousse food sample by conventional RT-PCR and qRT-PCR. Two fecal GII NoV samples and the orange mousse GII NoV sample were successfully genotyped as GII.Pe (ORF 1), revealed 98.0–98.8% identities among them, and shared phylogenetically distinct cluster. Establishing the source of a NoV outbreak can be a challenging task. In this report, the molecular analysis of the partial RdRp NoV gene provided a powerful tool for genotyping (GII.Pe) and tracking of outbreak-related samples. In addition, the same fast and simple extraction methods applied to clinical samples could be successfully used for complex food matrices, and have the potential to be introduced in routine laboratories for screening foods for presence of NoV. 相似文献
927.
A combined transmission electron microscopy (TEM) and Fourier transform analysis has been performed on the secretory granules storing active peptides/proteins in serous cutaneous glands of n?=?12 anuran species. Previous TEM investigation showed that the granules are provided with remarkable repeating substructures based on discrete subunits, arranged into a consistent framework. Furthermore, TEM findings revealed that this recurrent arrangement is acquired during a prolonged post-Golgian (or maturational) processing that affects the secretory product. Maturation leads to a variety of patterns depending on the degree of subunit clustering. This variety of recurrent patterns has been plotted into a range of frequency spectra. Through this quantitative approach, we found that the varying granule substructure can be reduced to a single mechanism of peptide/protein aggregation. 相似文献
928.
In this Concepts & Synthesis paper, we expand the definition of chronodisruption in humans by proposing that it can be operationalized as the split nexus of internal and external times. With this premise, we suggest how chronotype may be used as a temporal marker (chronomarker) of exposure to chronodisruption in studies of cancer, and beyond, offer cancer risk predictions for observational research on the basis of a chronotype-related hypothesis and corollary, and point to first empirical data in humans. In an a priori way, we examine possible outcomes and perspectives for preventive measures following from our rationale and the suggested chronobiology-driven studies and close with overall advances of chronodisruption research. 相似文献
929.
Jennifer L. Kelley Samuel C. Phillips Jonathan P. Evans 《Die Naturwissenschaften》2013,100(10):965-974
While behavioural plasticity is considered an adaptation to fluctuating social and environmental conditions, many animals also display a high level of individual consistency in their behaviour over time or across contexts (generally termed ‘personality’). However, studies of animal personalities that include sexual behaviour, or functionally distinct but correlated traits, are relatively scarce. In this study, we tested for individual behavioural consistency in courtship and exploratory behaviour in male guppies (Poecilia reticulata) in two light environments (high vs. low light intensity). Based on previous work on guppies, we predicted that males would modify their behaviour from sneak mating tactics to courtship displays under low light conditions, but also that the rank orders of courtship effort would remain unchanged (i.e. highly sexually active individuals would display relatively high levels of courtship under both light regimes). We also tested for correlations between courtship and exploratory behaviour, predicting that males that had high display rates would also be more likely to approach a novel object. Although males showed significant consistency in their exploratory and mating behaviour over time (1 week), we found no evidence that these traits constituted a behavioural syndrome. Furthermore, in contrast to previous work, we found no overall effect of the light environment on any of the behaviours measured, although males responded to the treatment on an individual-level basis, as reflected by a significant individual-by-environment interaction. The future challenge is to investigate how individual consistency across different environmental contexts relates to male reproductive success. 相似文献
930.
H. G. Thomas M. Scantlebury D. Swanepoel P. W. Bateman N. C. Bennett 《Die Naturwissenschaften》2013,100(11):1023-1030
Sociality in mole rats has been suggested to have evolved as a response to the widely dispersed food resources and the limited burrowing opportunities that result from sporadic rainfall events. In the most arid regions, individual foraging efficiency is reduced, and energetic constraints increase. In this study, we investigate seasonal differences in burrow architecture of the social Cryptomys hottentotus hottentotus in a mesic region. We describe burrow geometry in response to seasonal weather conditions for two seasons (wet and dry). Interactions occurred between seasons and colony size for the size of the burrow systems, but not the shape of the burrow systems. The fractal dimension values of the burrow systems did not differ between seasons. Thus, the burrow complexity was dependent upon the number of mole rats present in the social group. 相似文献